How to use a variable in: $this->index(); ?

[eluser]chefnelone[/eluser]
Ok, I see.
I'll remake my question:

Let's say I have 3 functions in a controller. When the index function is called it runs one of the other functions based in the value of $page.

Code:

function index(){
     $page = $this->uri->segment(1); //this can take the values: 'gallery', 'contact', anyOther...

     // if value of $page is 'gallery'
     $this->gallery();

     // if value of $page is 'contact'
     $this->contact();


    //I can't use switch() or if()
}
function gallery(){
    //anything
}
function contact(){
    //anything
}